Look at the picture and talk about the meaning of the formula. The idea of solving the problem is to understand the meaning and structure of the formula first, then disassemble the complex formula into simple parts through step-by-step calculation, calculate the results separately, and then combine these results to get the final answer.

Expressions are mathematical expressions expressed by mathematical symbols and numbers. It can represent a numerical value, a mathematical operation or a more complex mathematical structure.

In the process of understanding the formula, we need to pay attention to the meaning of mathematical symbols and the priority of operation. For example,+means addition,-means subtraction, x means multiplication,/means division, and () means that the operation in brackets takes precedence. If you encounter unfamiliar mathematical symbols or expressions, you can consult math books.

Common solutions of formulas:

1, direct calculation method: for a simple formula, the result can be directly calculated. For example, 3+4=7, 7x8=56 and so on.

2. Step-by-step calculation method: For complex formulas, step-by-step calculation method can be used. First, break the formula into several simple parts, calculate the results separately, and then combine these results to get the final answer. For example, (5x6)/2-8=7, you can first calculate the multiplication in brackets to get 30, then divide 30 by 2 to get 15, and finally subtract 8 from 15 to get 7.

3. method of substitution: For some formulas with unknowns, method of substitution can be used to solve them. Firstly, the unknown value is obtained according to the subject condition or known solution, and then the unknown value is substituted into the original formula for calculation. For example, given x=2 and finding the value of x 2+3x-4, we can substitute x=2 into the original formula and get 2 2+3x2-4 = 4+6-4 = 6.

4. Factorization: For some complicated formulas, factorization can be used to simplify the calculation. Factorization is to decompose a polynomial into the product of several factors, which can simplify the calculation process. For example, to find the solution of x 2-9 = 0, we can decompose the cause into (x+3)(x-3)=0, and then get x=-3 or x=3.

5. Graphical solution: For some geometric problems or functional problems, graphical solution can be used. Graphic solution is to turn the problem into a graph, and get the answer by observing and analyzing the properties of the graph. For example, to find the area of a triangle, you can draw a triangle figure, and then calculate the area according to the graphic attributes.